<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    class SuperClass{
        constructor(p){
            this.property=p;
        }
        showSup(){
            console.log("super:"+this.property)
        }
    }
    class SubClass extends SuperClass{
        constructor(sub,sup){
            super(sup);
            this.subproperty=sub;
        }
        showSub(){
            console.log("suber:"+this.subproperty)
        }
    }
    var sup=new SuperClass("Here");
    console.log(sup.property);
    var sub=new SubClass("sub","sup");
    console.log(sub.subproperty);
    console.log(sub.property);
    sub.showSub();
    sub.showSup();
</script>
</body>
</html>